Charging AGM Batteries

[Bauerg]

I have a 2019 28rbt and store it in my pole barn during the summer. I have a battery maintainer hooked up with one clip on the positive terminal of one battery and the negative post of the other battery terminal. They are AGM batteries and only a little over a year old. When I checked the batteries a week ago at the panel they were showing 12.7 volts a week ago. The charger has an AGM position and it was lit up and in the green like all was normal
Today, I checked at the panel and I showed 12.4 volts. Nothing is on other than the usual parasitic draw from the smoke detectors. My solar panel shows 60 per cent charge. There are no windows in the barn so the solar isn't operative. Should I disconnect the positive or negative terminal so the charger can get the batteries fully charged? I am concerned that I might ruin the batteries if the become fully discharged and I just want them maintained.

[dznf0g]

Originally Posted by Bauerg

I have a 2019 28rbt and store it in my pole barn during the summer. I have a battery maintainer hooked up with one clip on the positive terminal of one battery and the negative post of the other battery terminal. They are AGM batteries and only a little over a year old. When I checked the batteries a week ago at the panel they were showing 12.7 volts a week ago. The charger has an AGM position and it was lit up and in the green like all was normal

Today, I checked at the panel and I showed 12.4 volts. Nothing is on other than the usual parasitic draw from the smoke detectors. My solar panel shows 60 per cent charge. There are no windows in the barn so the solar isn't operative. Should I disconnect the positive or negative terminal so the charger can get the batteries fully charged? I am concerned that I might ruin the batteries if the become fully discharged and I just want them maintained.

What brand and model of battery maintainer?

[Wazbro]

I have a battery maintainer that defaults to 6v. I have to switch it to 12v every time I hook it to a battery, something to check. It says battery is fully charged when at 12.2v since that's more then full charge for 6v battery.

[richard5933]

12.2 is not fully charged for an AGM battery. A fully charged 12v battery should show something like 13.6v when plugged into the charger, and after sitting for a while unplugged and with no loads should be around 12.8v - 13.2v

What battery converter/charger is built into your trailer? If it's a modern multistage converter/charger, you don't need the battery maintainer - just use the one it's got.